Yoast SEO Plugin Slow
After installing the Yoast SEO plugin I experienced pages being slow to load (usually the first time you hit each page). It looked like mysql was causing the slowdown based on watching the process list. This showed mysql sleeping during the time that I was waiting for a page load. Alas, no slow queries showed up in the slow query log. Instead I noticed the following query in the general query log when the pause happens:
UPDATE `wp_options` SET `option_value` = '1439237518.7075259685516357421875' WHERE `option_name` = '_transient_doing_cron';
After a lot of searching on the web I found the solution. Disable the built in wp-cron and add manual cron entries. I suspect that Yoast SEO is adding some housekeeping stuff that is then causing a delay in the wp-cron load.
To disable the process, modify your wp-config.php to have the following line:
define('DISABLE_WP_CRON', true); Then modify your crontab: crontab -e To have a line for each site you disable:
*/5 * * * * curl -I http://example.com/wp-cron.php?doing_wp_cron